Why did another world war happened after World War 1?

America,France,England,Germany,Russia and other countries were'nt doing so well.The Nazi party took over Germany in 1933 and improved it's economy,improved it's army,navy,and air force.Germany annexed Austria in 1937,invaded Czcholazakia the Sudatenland in 1938,invaded Poland in 1939,that caused Britain and France to declare war on Germany.